A 2-phenyl-4-quinolone (2-PQ) derivative, 2-(3-fluorophenyl)-6-methoxyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (YJC-1), was
synthesized in our laboratory. In this study, we delineated the growth-inhibitory effect of YJC-1 in human lung carcinoma A549 cells. YJC-1
inhibited cell growth with an IC50 value of about 4.8 μM via microtubule polymerization, causing growth arrest in the mitotic phase.
Immunoblotting analysis revealed a dramatic induction of cyclin-dependent kinase (CDK) inhibitor p21Cip1/Waf1 and down-regulation of Cdc25C
phosphatase to inhibit the protein expression of cyclin B1 and CDK1. We also found that YJC-1 induced a profound time-dependent elevation in
p21Cip1/Waf1 gene expression in comparison with the negative control. In vivo, we also found that YJC-1 significantly suppressed tumor growth in
mice inoculated with A549 cells. These findings suggest that YJC-1 can suppress A549 cell growth via mitotic phase arrest.